1. Field of the Invention
The present invention relates to a vehicle including a leanable vehicle body frame and two front wheels.
2. Description of the Related Art
A known vehicle includes a vehicle body frame which leans in a left-and-right direction when the vehicle turns, and two front wheels arranged in the left-and-right direction of the vehicle body frame (for example, see Japanese Patent Unexamined Publication JP A-2011-195099).
The vehicle including the leanable vehicle body frame and two front wheels includes a link mechanism. The link mechanism includes an upper cross member and a lower cross member. In addition, the link mechanism includes a right side rod which supports right end portions of the upper cross member and the lower cross member, and a left side rod which supports left end portions of the upper cross member and the lower cross member. Intermediate portions of the upper cross member and the lower cross members are supported by the vehicle body frame directly in front of a steering shaft. In the vehicle disclosed in Japanese Patent Unexamined Publication JP A-2011-195099, the upper cross member and the lower cross member are supported by the vehicle body frame to be turnable around an axis orthogonal to a head pipe which is inclined so that a lower end thereof is positioned in front of an upper end (see Paragraphs [0023], [0024], and [0025] of Japanese Patent Unexamined Publication JP A-2011-195099). In accordance with the leaning of the vehicle body frame, the upper cross member and the lower cross member turn with respect to the vehicle body frame and relative positions of two front wheels in an up-and-down direction and a front-rear direction of the vehicle body frame change. In addition, the upper cross member and the lower cross member are provided above the two front wheels in the up-and-down direction of the vehicle body frame, in an upright state of the vehicle body frame.
The vehicle including the leanable vehicle body frame and the two front wheels includes a right shock absorbing device which movably supports the right front wheel in the up-and-down direction of the vehicle body frame, and a left shock absorbing device which movably supports the left front wheel in the up-and-down direction of the vehicle body frame. The right shock absorbing device is supported by the right side rod to be turnable around an axis of the right side rod. The left shock absorbing device is supported by the left side rod to be turnable around an axis of the left side rod. The vehicle disclosed in Japanese Patent Unexamined Publication JP A-2011-195099 further includes a handlebar, a steering shaft, and a turning transmission mechanism. The handlebar is fixed to the steering shaft. The steering shaft is supported to be turnable with respect to a head pipe of the vehicle body frame. When the handlebar is turned, the steering shaft also turns. The turning transmission mechanism transmits the turning of the steering shaft to the right shock absorbing device and the left shock absorbing device.
In the vehicle including the leanable vehicle body frame and the two front wheels, a riding space for a driver who operates the handlebar is provided behind the two front wheels.
In a vehicle including a leanable vehicle body frame and two front wheels, in accordance with the leaning of the vehicle body frame, an upper cross member and a lower cross member turn with respect to the vehicle body frame and relative positions of the two front wheels in an up-and-down direction and a front-rear direction of the vehicle body frame change. When the right front wheel moves downward and forward due to the turning of the upper cross member and the lower cross member, the left front wheel moves upward and rearward. When the right front wheel moves upward and rearward due to the turning of the upper cross member and the lower cross member, the left front wheel moves downward and forward. Accordingly, the movable ranges of the two front wheels in a front-rear direction of the vehicle body frame are large.
In addition, the vehicle including the leanable vehicle body frame and the two front wheels includes a riding space for a driver who operates a handlebar disposed behind the two front wheels. Accordingly, in an upright state of the vehicle body frame in which the two front wheels are not steered or leaned, a space for the front wheels to move in the front-rear direction is provided between the two front wheels and the riding space. Thus, the size of the entire vehicle including the leanable vehicle body frame and the two front wheels easily becomes large in the front-rear direction.
The vehicle disclosed in Japanese Patent Unexamined Publication JP A-2011-195099 includes a link-type right shock absorbing device and a link-type left shock absorbing device. In detail, the pair of right and left link-type shock absorbing devices include a bottom bridge which is provided below the side rods and extends forwards, a fork extending downward from a front end portion of the bottom bridge, a supporting arm of which one end portion is turnably supported with respect to the fork, an axle which is provided on the other end portion of the supporting arm and supports the front wheels, and a shock absorber which is provided between the bottom bridge and the supporting arm. In the link-type shock absorbing device, the front wheels also oscillate in accordance with the oscillation of the supporting arm. At that time, the shock absorber expands and contracts in accordance with the oscillation of the supporting arm. The oscillation of the front wheels is attenuated by the expansion and contraction of the shock absorber. Since the supporting arm is short and the shock absorber is supported by an intermediate portion of the supporting arm, a stroke of the shock absorber is short. In addition, since the supporting arm is short, a range of oscillation of the front wheels is narrow. Accordingly, the movable ranges of the right front wheel and the left front wheel in the front-rear direction of the vehicle body frame due to the operation of the link-type shock absorbing device are small. Since the link-type shock absorbing device is used in the vehicle disclosed in Japanese Patent Unexamined Publication JP A-2011-195099, the sizes of the movable ranges of the two front wheels in the front-rear direction of the vehicle body frame are prevented. Therefore, an increase in size of the entire vehicle in the front-rear direction is prevented.
However, in the link-type shock absorbing device, a stroke length of the right front wheel and the left front wheel due to the operation of the shock absorbing device is small. Accordingly, in the vehicle disclosed in Japanese Patent Unexamined Publication JP A-2011-195099, an increase in the size of the entire vehicle in the front-rear direction is prevented, but the stroke length of the right front wheel and the left front wheel due to the operation of the shock absorbing device is low, and thus riding comfort may be deteriorated.